Tropical Storm Iselle has made landfall on the Big Island of Hawaii at 2:30 a.m. local time, about five miles east of Pahala. Although the storm's winds had weakened below hurricane strength, Iselle still poses a threat to Hawaii's Big Island for several reasons.

Iselle is the first tropical storm to make landfall on the main Hawaiian Islands in 22 years, since 1992's devastating Hurricane Iniki hit Kauai. The storm is unique for approaching Hawaii from the east, where cool ocean waters and strong upper atmospheric winds typically overcome such storms and deflect them before they reach the island state. It is just the second tropical storm ever to hit the Big Island, and is the strongest to do so.

Hawaiians are not accustomed to these storms, and the 14,000 foot mountains on the Big Island will create unique hazards, possibly including mudslides and enhanced winds in some areas.

Iselle, which is moving at 10 mph, was expected to pass across the Big Island and then send rain and high winds to the rest of the state Friday. The storm's predicted track had it skirting just south of the other islands. And another hurricane is following in its path: Hurricane Julio, which strengthened to a Category 3 storm, is about 1,000 miles east-southeast of Hilo, Hawaii, and is expected to pass close to the islands on Sunday morning.

Even before its center touched land, tropical storm Iselle knocked out power on parts of the Big Island, one of the least populated islands. Iselle was expected to pass over the Big Island, known for coffee fields, volcanoes and black sand beaches, early Friday morning and then send rain and high winds to the rest of the state later in the day.

The rugged terrain of the Big Island means that some areas will see a lot more rain than others, as well as stronger winds. In fact, the nearly 14,000 foot-tall peaks of Mauna Loa and Mauna Lea can significantly speed up winds, much as city skyscrapers can, as the air is forced to squeeze into a narrow space between them. This is known as the venturi effect.

In addition, damaging surf of up to 25 feet in height and a 1-to-3-foot storm surge is causing coastal flooding on the Big Island. The storm is predicted to pass just to the south of Oahu, Maui and Kauai, where tropical storm warnings are in effect and the National Weather Service in Honolulu cautioned on Thursday evening that "only a slight change in the forecast track and intensity could lead to greater impacts" in the other Hawaiian islands.

"Whoop, there goes the power," 29-year-old Andrew Fujimura of Puna said as he spoke with an Associated Press reporter Thursday night. "It's fine. We'll just go to bed early tonight, I guess."

Fujimura was trading videos with a friend in Maui to help the friend see what weather conditions to expect. The videos show loud winds blowing through palm trees, white foamy waves chopping high onto shoreline shrubs and rocks — even a surfer riding rolling waves with an overcast sky on the Big Island's eastern shore.

Emergency officials on the Big Island sent a warning to nearby residents after a geothermal plant accidentally released an unknown amount of steam containing hydrogen sulfide, a smelly, poisonous compound. However, it was not clear whether the release was directly related to the storm.'

Hundreds of people flowed into emergency shelters set up at high schools on the Big Island, one of which lost power. Crews worked to restore electricity to the shelter in Pahoa with at least 140 people.

Two communities on the Big Island also lost power on Thursday evening: Waimea, a town of about 9,200 people near the island's north shore, and Puna, a district scattered with residents south of Hilo, Hawaii County Civil Defense officials said.

On Maui, power to a water treatment plant went out, prompting county officials to ask Kula residents in the middle of the island to conserve water.

Iselle is just the eighth tropical cyclone of tropical-storm intensity or greater to hit Hawaii in recorded history.

In preparation for Iselle, the state's schools will be closed on Friday, state offices closed (other than for emergency personnel) and tens of thousands of tourists told to stay put in their hotels.

Five thousand National Guardsmen have been summoned to assist in the preparations and aftermath of the storm, and California was standing by to help if supplies are needed from out-of-state.

"Whatever needs to be done we are ready," Governor Neil Abercrombie told reporters in a press conference Thursday.

The state won't have much time to clean up before it needs to prepare again, as a nearly unheard of second hurricane in less than 10 days — Hurricane Julio — will affect the state over the weekend. Most computer model projections show that the worst effects of Hurricane Julio will remain to the north of the main islands, but it could be a close call.

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